Endoscopic surgical instrument

ABSTRACT

An improved electrode for use with an endoscope, used for simultaneously vaporizing, coagulating and cutting of tissue. The construction of the electrodes is such that the connecting end joins an elongated stem having a conductive center conductor, a majority of which is enclosed by a cover constructed from nonconductive material for the purpose of insulating the conductor from the endoscope conduit, telescope and resectoscope sheath. The cover may have an insulated saddle shaped extension for use in guiding a telescope. The conductor divides into two insulated conductive branches, and then exits the insulative cover forming a loop at a distal end of the electrode. The distal end portion of the conductive loop may angle away from the axial direction of the electrode, and the loop is completed with a straight conductive portion upon which an electrode tip is rotatably mounted. Outward conductive tip surfaces have RF energy director points for increasing power density of RF energy coupled thereto from the conductor. The high power density vaporizes surface tissue, and simultaneously coagulates the underlying tissue as well.

RELATED CASES

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/637,327 filed Apr. 22, 1996 now U.S. Pat. No. 5,976,129which is a CIP if 08/259,712 filed Jun. 14, 1994, now U.S. Pat. No.5,562,703, which is a CIP of 08/025,003 filed Mar. 3, 1993, nowabandoned, which is a CIP of 07/779,108 filed Oct. 18, 1991, now U.S.Pat. No. 5,322,503.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a surgical instrument and more particularly toan instrument with the capability for continuous irrigation andevacuation of fluid into and out from a body cavity of a patient duringLaparoscopic or Endoscopic surgical procedures, and for the simultaneousmeasurement of tissue impedance and the ablation of tissue with fixed orretractable electrodes using R.F. energy.

2. Brief Description of the Prior Art

Laparoscopic/endoscopic surgical procedure allows a surgeon to seeinside the body cavity of a patient without the necessity of largeincisions. This reduces the chances of infection and other complicationsrelated to large incisions. The endoscope further allows the surgeon tomanipulate microsurgical instruments without impeding the surgeon's viewof the area under consideration.

During these surgical procedures it is desirable for as few lines aspossible to enter the body of the patient. This reduces the size of theincision the surgeon needs to make. It follows from this that thegreater the number of functions provided by a single instrument or thegreater the number of instruments able to be passed through a singleline entering the patient's body, the better.

Furthermore, in certain procedures it may be desirable to irrigate thearea under consideration. This in turn necessitates the evacuation ofthe irrigation fluid or, when bleeding has occurred, the blood or smokeor tissue residue generated by the surgical procedure.

From what has been said above it should be apparent that it ispreferable for both irrigation and evacuation to be conducted along asingle conduit which, also, acts as an access line for surgicalinstruments.

A typical device which is used in endoscopic procedures is anelectrosurgical probe. Typically such a probe will comprise a radiofrequency (i.e. R.F.) energy conductive tube covered with a dielectricmaterial such as polyolefin or Teflon. At one end, for conveniencecalled the operational end, each probe could have any one of a number offunctionally shaped monopolar or bipolar electrodes. In addition a probecould have its end formed specifically for irrigation and/or evacuation.

Monopolar and bipolar electrode probes are known in the prior art.Monopolar electrode probes include a single active electrode which issurgically introduced into a body cavity and engagable with andinsertable into a tissue portion of the cavity. A passive electrode isattached to the outer body surface of the patient, e.g. typically aconducting plate is adhesively attached to the patient's leg. The bodyof the patient serves to complete the electrical circuit. Tissueablation and coagulation is achieved by introducing sufficient powerinto the active electrode. Bipolar electrode probes include both activeand passive electrodes which are similarly introduced together into thebody cavity and are spaced apart from each other by a predetermineddistance. Each electrode is engageable with and insertable into thetissue portion. Thus, the electrical circuit is completed by the bodytissue disposed between the active and the passive electrodes and onlythe body tissue disposed between the two electrodes get coagulated.

In surgical operations it is often desirable to remove layers of bodytissue. Such an operation can be readily performed if the affected areais totally exposed and large surgical devices can be used. However,large surgical openings are not desirable, due to the resulting bodilytrauma, and exposure to the environment which increases the risk ofinfection. Endoscopic surgery minimizes body trauma and the risk ofinfection, but the devices of the prior art have significantlimitations. FIGS. 29-32 show prior art devices. FIGS. 29-31 illustratea roller ball, a flat roller bar, and a grooved roller bar respectively.These devices apply RF energy over a significant area and have provenuseful for coagulating tissue to reduce bleeding, but they are notuseful for tissue vaporization due to low power density. FIG. 32 shows athin wire loop that concentrates the RF energy and is effective incutting tissue, but does not function to coagulate, and therefore itsuse results in significant bleeding which makes it difficult to use inan endoscope due to the time required to remove a cutting electrode andinsert a coagulation electrode, and due to the build-up of blood whichthen needs to be evacuated in order to view the work through theendoscope. There is clearly a need for a surgical device that can removetissue and simultaneously coagulate the resulting exposed tissue. Use ofsuch a device would leave the surgeon's view unobstructed by blood, andreduce the chance of infection. As a result, more extensive and safersurgery could be performed.

Furthermore, any valves controlling the evacuation and irrigationprocedures should be constructed so as to minimize the possibility ofthe valve malfunctions if, for example, any tissue or blood coagulatesaround their moving parts. Similarly if any of the instrumentation is tobe reusable, such instrumentation, including the valves, should becapable of being efficiently cleaned by, for example, flushing.

U.S. Pat. No. 4,668,215 (Allgood) discloses a valve for switchingbetween an evacuation-and an irrigation conduit and allowing both suchevacuation and irrigation to be done via a single line entering thepatient. The mechanism for switching between the irrigation, evacuationand closed configurations is by means of a L-valve or T-valve. Thispatent, in another embodiment thereof, further provides for a pistonvalve for making an on-off connection between an evacuation port and theline leading into the patient.

The L- and T-valves have the disadvantage that they must be manipulatedby rotation by the surgeon, usually using his/her free hand. The pistonvalve disclosed in this patent has the disadvantage that it has manyareas where blood and tissue accumulation and coagulation can occurwhich may result in the malfunctioning of the valve. In addition, thepiston valve has numerous “dead” areas where fluid flow would not occur.This precludes the device from being effectively cleaned by commonlyused flushing techniques. Finally, the Allgood patent does not disclosea single body for housing an evacuation/irrigation control valvetogether with a housing for laparoscopic and microsurgicalinstrumentation.

A surgical valve that the applicant is aware of is the piston valveillustrated in FIG. 1 of the accompanying drawings.

In this valve a piston 10 is located within a cylinder 11. The piston 10can be moved along the bore of the cylinder 11 by means of a plunger 12,from a closed position (as shown) to an open position in which a conduit13 is aligned with an access port 14. This allows fluid flow along apath to or from access port 14, via conduit 13 and space 16 from or to afurther port 15. Upon release of the plunger 12 the piston 10 returns toits closed position under action of a spring 17.

This valve, although easy to use, has the disadvantage that blood andtissue accumulation occurs in space 16 and clogs both the space and thespring 17. This may result in undesirable over-evacuation or irrigationof the patient during surgical procedures.

OBJECTS OF THE INVENTION

It is therefore an object of this invention to provide a surgicalinstrument which includes control means to allow for the continuousirrigation and evacuation of a body cavity of a patient duringmicrosurgical procedures, with both irrigation and evacuation beingperformed along a single line into the patient. The instrument shouldalso act as a mounting for electrosurgical probes and microsurgicalinstruments.

A further object of the invention is to provide a configuration for aninstrument which, depending on the material it is constructed of, can beboth disposable and non-disposable. In the event that the instrument is“reusable” or “reposable” it is an object of the invention to providethe instrument with conduits, access ports and valves which can easilybe cleaned by means of commonly used cleaning techniques andconventional sterilization methods.

It is another object of the invention to provide an electrosurgicalinstrument with fixed or retractable RF electrodes having the capabilityto simultaneously perform controlled ablation of tissue usingmonopolar/bipolar R.F. energy and precise measurement of tissueimpedance.

An object of the present invention is to provide an adjustable area oftissue coagulation, which may be larger or smaller than the size of theprobe enclosing the electrodes. A further object is to provide multiplebipolar electrodes to allow a larger zone of coagulation. The spacing ofthe multiple electrodes may be adjusted for larger or smallercoagulation zones.

Another object of the present invention is to provide a singleconnecting cable system for use with an RF energy source and an RFelectrode means whereby either the monopolar or bipolar output mode fromthe energy source may be selected and used with a single RF electrodemeans. The connecting cable system permits use of the single electrodemeans for either RF output mode (monopolar or bipolar, which aretypically labelled CUT and COAG, respectively on commercially availableRF generators), and the user may elect the output mode while theelectrode means are in situ.

Still another object of the invention is to provide a method forhysteroscopic and laparoscopic treatment of uterine fibroids/myomas withmonopolar or bipolar electrosurgical instrumentation for controlledablation of tissue.

It is a further object of the present invention to provide an RFelectrode for use with an endoscope that can cut and coagulate tissuesimultaneously.

It is another object of the present invention to provide an RF electrodefor use with an endoscope that can vaporize and coagulate tissuesimultaneously.

It is a further object of the present invention to provide a method ofcutting, coagulating and vaporization of tissue using an isotonicsolution to conduct RF energy in monopolar or bipolar operation.

It is a still further object of the present invention to provide an RFelectrode having non-conductive material to isolate RF energy from theendoscopic instrument resectoscope, telescope and working element.

It is a still further object of the present invention to provide abipolar RF electrode for use with an endoscope that can resect, vaporizeand coagulate tissue.

SUMMARY OF THE INVENTION

According to this invention, an endoscopic surgical instrument comprisesan irrigation and an evacuation port, each port being connected throughindependent valves to a single access conduit; a probe connector locatedat one end of the access conduit, the probe connector being forreceiving and retaining a hollow surgical probe; and a monopolar orbipolar radio frequency connector which exits into the access conduit insuch a manner so as to make radio frequency connection with a probereceived by the probe connector.

Preferably the connector for receiving an end, for convenience calledthe locating end, of the probe would be in the form of a receiving borein the access conduit which would include a plurality of O-rings whichprovide a fluid-tight seal around the locating end of the probe. TheseO-rings also function to retain the probe in the receiving port whileallowing the probe to be rotated. In one embodiment of the invention,the O-rings are, instead of being located within the receiving bore ofthe access conduit, located about the locating end of the probe.

This invention also provides for a valve, for use as either anevacuation or an irrigation valve, the valve comprising a housing, anactivator connected to the housing, at least a first and a second valveaccess conduit, both of which exit into the housing and a fluidimpervious seal mounted within the housing such that activation of theactivator causes the first valve conduit to move axially relative to theseal and the second valve conduit such that the seal is disengaged andthe conduits are placed in direct fluid communication with each other.

Typically, the instrument of the invention would contain two of theabove described valves. One valve would act as an evacuator controlwhile the other valve would act as an irrigation control. Both valvescommunicate into a single access conduit which, when the instrument isin use, continuously flows into the patient via the receiving bore andthe hollow interior of the electrostatic probe.

Preferably the endoscopic surgical instrument of the invention is in theform of a pistol with the “barrel” portion thereof having, at one endthereof, the receiving bore for the locating end of the endoscopic probeand, at the other end thereof, the access port for the microsurgicalinstruments and endoscopes.

The valves for controlling the evacuation and irrigation procedures maybe mounted in the “handle” portion of the pistol-shaped instrument. Thevalves may be mounted alongside one another in the handle portion andmay protrude therefrom to allow finger control by the surgeon using theinstrument.

In one alternate embodiment of the invention the surgical instrumentincludes a housing, a single access conduit formed in the housing, anirrigation port and an evacuation port, each port being connectedthrough independent valves to the single access conduit. The singleaccess conduit has a first end, and a second end which is terminated inan aperture formed in the housing. A closure is provided for theaperture. A viewing device, such as an endoscope, is insertable throughthe aperture and into the single access conduit. The viewing device isof sufficient length such that it is extendable slightly beyond thefirst end. A retractable electrode assembly is also insertable throughthe aperture and into the single access conduit, and is of sufficientlength such that it, too, is extendable beyond the first end. Theretractable electrode assembly, in one embodiment, includes tworetractable RF electrodes spaced apart by a predetermined width. Each RFelectrode is made from a superelastic material, e.g. typicallyNickel-Titanium (NiTi) metal, is sheathed within a guiding sheath, andis slidable within the sheath such that it is extendable beyond andretractable completely within the sheath. Also, each electrode isconnected to a mechanism, operable by a surgeon, for moving theelectrode within the sheath. Each electrode is extendable beyond itsguiding sheath by a variable length and at a predetermined angle from alongitudinal axis of the single access conduit. Further, each electrodeis electrically communicative with means for supplying R.F. energy andmeans for measuring impedance continuously on a realtime basis.

The present invention includes improved electrodes for simultaneouslyvaporizing, coagulating and cutting of tissue. The electrodes have aconnecting end for making contact to an endoscopic device and an RFenergy source. In the preferred embodiment, the construction of theelectrodes is such that the connecting end joins an elongated stemhaving a conductive center conductor,sa majority of which is enclosed bya cover constructed from non-conductive material for the purpose ofinsulating the conductor from the endoscope conduit, telescope andresectoscope sheath. The cover also preferably has a saddle shapedextension, also preferably constructed of non-conductive material, foruse in guiding a telescope. The conductor divides into two insulatedconductive branches forming a loop at a distal end of the electrodeopposite the connecting end. In a preferred embodiment, the distal endportion of the conductive loop angles away from the axial direction ofthe electrode, and the loop is completed with a straight conductiveportion forming an axle for supporting a conductive roller thereon. Theoutward conductive roller surface has RF energy director points forincreasing power density of RF energy coupled thereto from theconductor. The high power density vaporizes surface tissue, andsimultaneously coagulates the underlying tissue as well. An alternateembodiment includes a standard loop shaped cutting electrode tipfollowed by a similarly shaped loop electrode with an enlargenedconductor for coagulating the tissue exposed by the cutting tip.

An advantage of the present invention is the provision of an electrodethat can both vaporize tissue for removal, and coagulate the underlyingtissue to reduce bleeding.

A still further advantage of the present invention is a reduction inoperating time because there is no need to change electrodes from acutting electrode to a coagulating electrode.

Another advantage of the present invention is that it provides anendoscopic surgical instrument having an electrode, operable in eithermonopolar or bipolar mode, and with or without an isotonic solutionallowing improved control over the area and volume of tissue treated,thereby eliminating the need for a conventional patient electricalreturn pad, reducing damage to surrounding healthy tissue.

These and other objects and advantages of the present invention will nodoubt become apparent to those skilled in the art after having read thefollowing detailed description of the preferred embodiment which isillustrated in the several figures of the drawing.

IN THE DRAWINGS

In the following drawings:

FIG. 1 is a partial sectional elevation through a prior art pistonvalve;

FIG. 2 is a diagrammatic section through a semi-exploded elevation ofone embodiment of the endoscopic surgical instrument of the invention;

FIGS. 3A-3B illustrate a tricuspid valved access port in plan (a) andelevation (b) views;

FIG. 4A is a section through a receiving bore of the instrumentillustrating one way of locating a probe in the bore;

FIG. 4B is an illustration of a probe for use with the connector shownin FIG. 4A;

FIG. 5A is a section through a similar receiving bore showing adifferent way of locating a probe in the bore;

FIG. 5B is an illustration of a probe for use with the connector of FIG.5A;

FIG. 6 is a side view illustrating in (a)-(i) various electrostaticprobe operational ends;

FIG. 7 is a section through a valve according to the invention with thevalve being in the shut position;

FIG. 8 is the valve of FIG. 7 in the open position;

FIG. 9 is a partial section through a different type of valve alsosuitable for use in the instrument of the invention;

FIGS. 10, 11, 12 and 13 are diagrammatic illustrations showing variousconfigurations of valve operating buttons and triggers;

FIG. 14 is an exploded view of an alternative embodiment of the surgicalinstrument of the invention illustrating a disposable valve cartridge;

FIG. 15 is a cross section through the disposable valve cartridgeillustrated in FIG. 14;

FIG. 16 is a partially sectioned view of another type of valve which canbe used in the surgical instrument of the invention;

FIG. 17 is a perspective view of an alternate embodiment of theendoscopic surgical instrument having generally similar valves, asillustrated in FIGS. 7-8, and a retractable electrode assembly havingbipolar RF electrodes in electrical communication with a R.F. energysource and a tissue impedance monitoring device;

FIG. 18 is a partial sectional view taken along the line 18—18 of FIG.17;

FIG. 19 is a view taken along the line 19—19 of FIG. 17;

FIG. 20 is a side elevation view of the retractable electrode assemblyshown in FIG. 17;

FIG. 21 is an enlarged view of the tip of the retractable electrodeassembly shown in FIG. 17;

FIGS. 22A-22H illustrate alternate electrode configurations for theretractable electrode assembly shown in FIG. 17 and 20;

FIG. 23 is an enlarged view of the tip of the retractable electrodeshown in FIGS. 22D-22F; and

FIG. 24 is an alternate embodiment of the present invention including aretractable electrode assembly having a variable angle controlmechanism.

FIG. 25(a) is an illustration of the use of multiple electrodes orientedat an angle theta;

FIG. 25(b) shows an end view of the electrodes of FIG. 25(a) providing arectangular pattern;

FIG. 25(c) shows a view similar to FIG. 25(b), in which two electrodesare used;

FIG. 25(d) illustrates the use of three electrodes for obtaining anapproximate circular coagulation pattern;

FIG. 25(e) illustrates the use of four electrodes to achieve anapproximate circular coagulation pattern;

FIG. 25(f) shows the use of nine electrodes to achieve an improvedcircular pattern;

FIG. 26(a) illustrates the use of superelastic metal electrodes toachieve an adjustable pattern;

FIG. 26(b) further clarifies the configuration of FIG. 26(a);

FIG. 27 illustrates the use of a frusto-conical extension for deflectingthe electrodes to achieve an adjustable zone of coagulation;

FIG. 28 shows a connecting cable system for selectively applying bipolaror monopolar RF power to the electrodes.

FIGS. 29-32 illustrate prior art RF electrodes;

FIG. 33 shows an alternative style of endoscopic device with electrodemovement mechanism;

FIG. 34 shows an electrode with a field enhancement tip;

FIG. 34A shows an insulated electrode with a telescope guide and acutting loop;

FIG. 34B shows an insulated electrode with a telescope guide and aroller electrode tip;

FIG. 34C shows an insulated electrode with a telescope guide and a fieldenhancement tip;

FIG. 34D illustrates a dual electrode tip apparatus for bipolaroperation;

FIG. 34E shows an insulated electrode with-a telescope guide installedin a probe housing;

FIG. 35 shows a tip module and interconnection with an electrode stem;

FIG. 36 shows an alternate electrode tip module and stem;

FIG. 37 shows the alternate module and stem interconnected;

FIG. 38 shows a roller tip on a tip module;

FIG. 39 shows a cutting loop on a tip module;

FIG. 40 shows two roller tips on a tip module;

FIG. 41 is a cross sectional view of the rotatable mounting of a rolleron an electrode conductor;

FIG. 42 illustrates the RF field concentration for a roller withdisk-like protrusions;

FIG. 43 illustrates the RF field concentration of a prior art deviceused for coagulation;

FIG. 44 is an illustration of a roller vaporizing and coagulatingtissue;

FIG. 45 shows a roller tip with helical shaped energy directors;

FIG. 46 shows the roller tip with grooves cut across the helical shapedenergy directors;

FIG. 47 shows a roller tip having a star configuration;

FIG. 48 illustrates the use of narrow edged disks on an electrode wire;

FIG. 49A shows narrow edged disks on a semicircular shaped electrodeconductor;

FIGS. 49B-49D show alternative roller loop electrode configurations;

FIG. 50 is a pictorial view of a roller tip with a plurality of reducedarea energy directors;

FIG. 51 illustrates an electrode with a coil wire tip;

FIG. 52 illustrates an electrode using two field enhancement roller bartips for monopolar operation;

FIG. 53 shows an electrode having a narrow wire electrode and avaporizing roller loop electrode for monopolar operation;

FIG. 54 illustrates the use of two field enhancement roller barelectrodes for bipolar operation;

FIG. 55 shows two coil electrodes interwound for bipolar operation;

FIG. 56 illustrates the use of a thin wire electrode (active) forconnection to the active side of an RF supply for cutting and a rollerelectrode (return) for connection to the return side of the RF supplyfor coagulation, in bipolar operation;

FIG. 57A illustrates the use of a thin wire electrode (active) forcutting and a thicker electrode (return) for coagulation for bipolaroperation;

FIGS. 57B-57E illustrate various electrode cross section shapes;

FIG. 58 shows two vaporizing roller loop electrodes illustrating theindependent disks on semicircular wires, arranged for bipolar operation;

FIG. 59 shows two thin wire electrodes in a bipolar configuration;

FIG. 60 illustrates a roller loop vaporizing electrode with independentdisks in combination with a roller electrode for bipolar operation; and

FIG. 61 illustrates an integrated bipolar electrode using roller disks.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 2 of the accompanying drawings, the endoscopic surgicalinstrument of the invention is generally indicated as 20. The instrument20 is shown to include an irrigation port 21 and an evacuation port 22.Each port, 21 and 22, is connected through independent valves 23 and 24,respectively, to a single access conduit 25. The connection between thevalves 23 and 24 and conduit 25 is along connector tubes 23 a and 24 a.

The access conduit 25 leads from the valves and their respective valveconduits to a probe connector 26. This probe connector 26 is designed toreceive one end, the locating end 27, of a surgical probe 28 which wouldbe used during microsurgical procedures. The connection 26 is describedin more detail with reference to FIGS. 4 and 5 hereafter.

At or near the probe connector 26, a monopolar/bipolar radio frequencyconnector 29 is located. As illustrated, this is in the form of a R.F.connector. The advantage of a R.F. connector is that it is an industrystandard and can be used for connecting the instrument 20 to standardR.F. energy sources marketed by a number of different manufacturers.

The radio frequency connector 29 exits into the access conduit 25 whereit makes connection with a point 30, on the locating end 27 of a probe28 received by the probe connector 26.

The surgical instrument 20 also includes a port 31 which allows thesurgeon to insert microsurgical instrumentation and viewing devicesalong the access conduit 25 and the bore of the hollow probe 28 to exitfrom the end 32 thereof. The port 31 should provide a fluid-tight sealwhen no microsurgical instrumentation is being used with the surgicalinstrument 20. This will prevent fluid, which may be moving along theaccess conduit 25 to or from the patient, from leaking.

Typically, the access port 31 is in the form of a commercially availabletricuspid valve as illustrated in FIGS. 3(a) and (b). In these figures,the valve 31 is shown as being constituted by three segments. 32 whichin plan view are wedge-shaped and which together form the disc shapedsealing portion of the valve. The segments 32 are held together by meansof a circumferential ring 33 which biases the three segments 32 togetherto form a fluid-tight seal. In use, the microsurgical instrumentationare inserted through the valve at a point 34 where the apexes of thesegments 32 come together. This insertion forces the elements of thevalve apart to allow ingress of the microsurgical instrumentation. Theeffect thereof is shown in broken lines in FIG. 3(b). When theinstrumentation is removed from the valve 31, the segments 32 are pulledtogether to form the seal.

In FIG. 4 the probe connector 26 is shown to be constituted by areceiving bore which is coaxial with the fluid access conduit 25. Inpractice, the diameter of this bore would be the same as that of theaccess conduit 25 and would be sized to receive the locating end 27 ofthe probe 28 in a relatively close fit. Within the bore forming theprobe connector, a plurality, typically two, O-rings 36 are located.When the locating end 27 is inserted into the bore 26 these O-ringsprovide a snug, fluid-tight seal about the end 27. Once the locating end27 of the probe is received within the bore 26 it is capable of beingrotated about its longitudinal axis, by means of a knurled rotation knob37 located between the locating end 27 and the operational end 32 of theprobe 28.

The probe 28 would typically be made of a electrostatic conductivematerial coated with a non-conductive material such as heat shrinkpolyolefin or Teflon. Electrostatic/radio frequency energy is passedalong the probe 28 from the radio frequency connector 29 viaelectrostatically conductive plates 38 located within the bore of theprobe connector 26 and onto the end 30 of the probe 28. The end 30 is sodesigned such that when the locating end 27 of the probe is received bythe probe connector 26, electrostatic connection is made between theplate 38 and the connector 30. This allows the surgeon to pass energyinto the patient being operated on.

An alternative radio frequency connector is illustrated in FIG. 5. Inthis case, the R.F. connector 29 exits into the bore in the form of apin 39. In the conductive end 30 of the probe an L-shaped slot 40 isformed. As the probe 28 is inserted into the receiving bore 26, the pin39 engages the axially-orientated leg 41 of the L-shaped slot 40. Whenthe probe can be inserted no further along the bore it is twisted, inthis case in an anti-clockwise direction, such that the pin 39 and theaxially transverse leg 42 of the L-shaped slot 40 engage each other tolock the probe 28 into position. In this embodiment the probe 28 cannotbe rotated by means of the knurled knob 37.

FIG. 5 further illustrates an alternative positioning of the O-rings 36.In this case they are located on the locating end 27 of the probe 28.

From FIGS. 4 and 5, although not shown, it will be apparent that thediameter of the operational shank 28 a of the probe 28 can be variable.Typically, the probe, as shown, would have a diameter of 5 mm. Thisdiameter can, however, be increased to 10 mm which would be close to thediameter of the locating end 27 of the probe, as well as that of theinternal bore diameter of the access conduit 25. The advantage of 10 mmdiameter probes is that the evacuation of removed tissue and objectssuch as the gall-stones can be more effectively achieved. Obviously,when the bore of the operating shank 28 a of the probe, the locating end27 and the access conduit 25 are all 10 mm in diameter, the diameter ofthe evacuation port 22 and its related valve 24 and connector tube 24 amust also be 10 mm.

In FIG. 6(a) to (i), a side view of number of different electrode shapesare illustrated. It will be appreciated that the electrode tips could beeither monopolar or bipolar. In the case of bipolar electrodes, only oneelectrode is illustrated since a second electrode is fully obscured bythe visible electrode. These electrode tips would be located on theoperating end of the probe 28.

As can be seen from the figure, a number of the tips are not symmetricalabout the longitudinal axis of the probe 28. It is for this reason thatit is desirable for the probe 28 to be mounted on the instrument in sucha manner to allow for a rotation of the probe about its longitudinalaxis. As has been previously indicated, this will give the surgeon theopportunity of rotating any non-symmetrical tips, inside the patient,without having to rotate his or her wrist.

This invention extends also to an electrostatic probe 28, substantiallyas described in any of the FIGS. 4 to 6.

The details of one type of irrigation/evacuation valve are illustratedin FIGS. 7 and 8. The valve 24 indicated in both figures comprises ahousing constituted by a hollow tube 50 and an activator in the form ofa button 51 formed integrally with the tube 50. A fluid impervious seal52 is located within the tube 50. Referring specifically to FIG. 7, inwhich the valve is shown in the shut position, it can be seen that theseal 52 lies between a first valve conduit 53 which leads to theevacuation port 22 (not shown) and a second valve conduit in the form ofconnector tube 24 a which leads into the primary access conduit 25 ofthe surgical instrument. In effect, the seal 52 prevents the conduits 53and 24 a from being in communication with each other.

The first valve conduit 53 is mounted onto the wall of the tube 50 andopens into the interior of the tube 50 through a hole 54. Between theseal 52 and the button portion 51 of a tube 50, a spring 55 is located.On the side of the seal 52, opposite to which the spring is located, atubular insert 56 is located. This tubular insert has a snug butslidable fit over the outer wall of the second valve conduit 24 a aswell as a tight, fluid impervious fit into the inner bore of the tube50. This tube 56 acts as a stop which prevents the spring 55 frompushing the seal 52 out of the hollow tube 50.

To open the valve, as is illustrated in FIG. 8, an activating force,applied along a line F to the button 51, will cause the button to movefrom the position indicated in broken lines to the illustratedopen-valve position. As the button moves, so does the hollow tube 50,taking the first valve conduit 53 along with it. In addition, theleading edge 57 of the second valve conduit 24 a bears against the seal52 causing the seal to move relatively to the tube 50. This in turndisengages the seal from sealing the hole 54 in the wall of the tube 50.The movement of the first valve conduit 53, relative to the second valveconduit 24 a, places the respective openings 54 and 58 of these twoconduits in fluid communication with each other thereby allowing anunobstructed fluid flow along both access conduits.

Upon release of the force on the button 51, the bias of the spring 55will return the valve to its shut position.

It is evident from the construction of the valves illustrated in FIGS. 7and 8 that they can be readily cleaned by commonly used cleaning such asflushing. In addition, the valves have almost no areas where blood andtissue accumulation and coagulation can occur, and if such accumulationand coagulation does occur the valves cannot be jammed in the openposition. This is because the spring biasing the valve into its closedposition is located in an effectively sealed area. Furthermore thesevalves have been tested to a pressure of up to 100 psi without theintegrity of the valve seal being adversely affected.

An alternative form of valve, to that illustrated in FIGS. 7 and 8above, is shown in FIG. 9. In the figure the valve is shown to include agenerally cylindrical valve body 60, an activating button 61 and aplunger 62. A hollow bore runs down the center of the valve body 60 andcontains the valve seal 63. The valve seal 63 is made up of a circularwasher 63 a and a sealing O-ring 63 b and is screwed onto the bottom ofplunger 62. The valve seal 63 is biased into its illustrated sealingposition by means of a spring 64 located in the bottom part of the valvebody 60.

To open the valve, the button 61 is depressed so that the plunger 62forces the valve seal 63 downwards against the bias of the spring 64 toa position shown in broken lines 63′, in the figure. As a result, afluid path, indicated by arrows 65, is opened between an upper pair ofcutouts 66 and a lower pair of cutouts 67. Each pair of cutouts opensinto the hollow bore in the center of the valve body 60 and, when thisvalve is inserted into the surgical instrument, into either anevacuation or irrigation conduit. Closure of the valve is achieved byreleasing the button and allowing the spring 64 to return the valve seal63 to the sealing position.

One advantage of this embodiment of the valve is that it is easilyremoved from and inserted into the surgical instrument of the invention.Accordingly the valve can easily be removed for cleaning or disposal andreplacement. This is further illustrated below with respect to FIG. 13.It is sufficient here to mention only that the surgical instrument isprovided with a receiving bore for each valve and that the valveincludes a plurality (in this case 3) O-rings 68 which, when the valveis inserted into its respective receiving bore, provide a number offluid tight seals against the inside of the bore.

Either of the two types of valve described in FIGS. 7 to 9 can be usedon the instrument 10. Typically one valve would act as an evacuationvalve while the other as an irrigation valve. Different types ofarrangements of valves and valve activation means are illustrated in thefollowing 4 figures.

One way of activating the valve is by means of a rocker-shaped trigger70 illustrated in FIG. 10. The trigger 70 is pivotally mounted on apoint 72 on the handle. 74 of the pistol. Depressing the trigger 70 tooperate the irrigation valve 71 would not interfere with the operationof the evacuation valve 73. Similarly, operation of the trigger 70 tooperate the evacuation valve 73 would in no way effect the operation ofthe irrigation valve.

In FIG. 11 a trigger mechanism 76 is shown for operation of only one ofthe buttons. The other button 78 would be located for operation by meansof the surgeon's thumb in a position removed from the trigger 76. Thiscould, for example, be near the top end of the handle portion of theinstrument.

Yet a further positioning of the buttons 71 and 73 is indicated in FIG.12. In this instance, the buttons protrude from the top rear of thepistol handle and are located side-byside. To prevent confusion betweenevacuation and irrigation procedures, the tops of the buttons havedifferent shapes. So, for example, the button to manipulate theevacuation valve could be concave while the button for manipulating theirrigation valve could be convexly shaped.

FIG. 13 illustrates still another arrangement of buttons and valves, inthis case an arrangement particularly suited to the valve shown in FIG.9.

In this figure only the pistol grip 90 of the surgical instrument of theinvention is shown. An irrigation port 92 and evacuation port 94 enterthe pistol grip 90 at the bottom of its handle portion. The ports 92, 94are, in use, respectively connected to irrigation and evacuationconduits (not shown) and, to this end, suitable connectors, asillustrated, are provided.

The irrigation port 93 communicates with the main access conduit 96(referenced as 25 in FIGS. 2, 4 and 5) along an irrigation conduit 98which extends from the irrigation port 93 and into the rear of the bore100 which houses an irrigation valve 102. From there it extends alongthe bore 100 to a point near the front of the bore from where it exitsinto the body of the grip 900 to enter rear of the bore 104 which housesan evacuation valve 106. the irrigation conduit extends directly acrossthe bore 104 at this point and becomes-a central conduit 108 whichcommunicates with the access conduit.

On the other hand, the evacuation port 94 communicates with anevacuation conduit 105 which extends along the pistol grip 90 directlyinto the front of the bore 104, down to the bore 104 to its rear fromwhere it exits into the central conduit 108.

In the position shown, both the irrigation and evacuation valves 102,106 respectively, are shown in the off or shut configurations andneither evacuation or irrigation can take place. Should irrigation ofthe patient be required, the dish-shaped irrigation button 110 isdepressed and the valve 102 opens (ie. its valve seat moves to the rightin the drawing) to allow irrigation fluid to pass along the irrigationconduit 98 and into the bore 104. In this bore 104 the evacuation valve106 is in the off configuration. However, a fluid path exists across thepair of cutouts (67 in FIG. 9) and therefore the irrigation fluid canpass through the body of the valve 106 and into the central conduit 108and, from there, into the access conduit 96.

When evacuation is desired the irrigation button 110 is released and thespring associated with the irrigation valve 102 biases it into the shutor off configuration. Thereafter the flat topped evacuation button 112is depressed to open the evacuation valve 106. This allows the patientto be evacuated along the main access conduit 96, into the centralconduit 108, then from the rear to the front of the bore 104 and, fromthere, out along the evacuation conduit 105.

As has been indicated earlier, the valves 102, 106 are easily insertedinto and removed from their respective bores 100, 104. This allows thepistol grip 90 (which is typically stainless steel and is reusable) tobe cleaned efficiently. The valves, typically being of plastic and beingdifficult to clean, can be discarded and replaced with new valves.

A variation on this theme of discardable valves is illustrated in FIG.14. In this figure the surgical instrument is shown to include a pistolgrip 120, a surgical probe 122, which can be screwed into the front ofthe pistol grip 120 and a radio frequency connector 124 which screwsinto the back of the grip 120.

The instrument also includes a removable (and disposable) valvecartridge 126. The cartridge 126 includes an irrigation pipe 128 and anevacuation pipe 130 both of which are individually operated by valves(as will be further illustrated in FIG. 15) under action ofbutton-shaped actuators 132. Both the irrigation and evacuation pipescommunicate into a single conduit (not shown) which runs down the centerof a male connector fitting 134. Where the cartridge 126 is insertedinto the grip 120 the connector 134 fits into the base of a centralconduit 136 which, in turn, opens up into the main access conduit 138 ofthe instrument. When the cartridge 126 is located in the grip 120 theactuators 132 are located directly below a pair of operating triggers140 which can be used to operate the irrigation/evacuation proceduresdescribed before.

Finally, when the cartridge 126 is in place, it is held there by meansof a retainer clip 142 which clips in behind the cartridge 126. Theretainer clip 142 has apertures 144 formed in it to allow the irrigationand evacuation pipes 128, 130 to pass through it.

Although it will be apparent that the valve types described above arealso suitable for use in the cartridge 126, a further valveconfiguration is illustrated in FIG. 15, which illustrates the cartridge126 in greater detail.

In this figure, the cartridge 126 is shown to include an irrigationconduit 150 and an evacuation conduit 152, both of which lead to acentral access conduit 154 which extends down the center of the maleconnector 134. Irrigation and evacuation procedures are controlled byirrigation and evacuation valves 156 and 158, respectively.

The irrigation valve 156 consists of a valve seal 160 mounted onto astem which is screwed into an activator button 132 a. A fluid tight sealis provided for the valve 156 by an O-ring 168 mounted onto the cap 132a. The valve seal 160 seals against a valve seat, formed at the junctionbetween the irrigation conduit 150 and the central access conduit 154and is held in the sealing position (as shown) by a spring 162.

Access to the valve seat is through a hole 164 formed into the top (asshown in the drawing) of the cartridge 126. This hole 164 can be closedoff with a cap 166 and allows the irrigation valve 156 to be insertedinto the cartridge 126. This is done by inserting the valve seal 160 andits associated stem into the hole 164 from above and inserting thespring 162 from below. Thereafter the cap 132 a can be screwed onto thestem to hold the entire valve 156 in place.

To operate an irrigation procedure the button 132 a is depressed to movethe valve seal 160 clear of its seal to open a fluid path between theirrigation conduit and the central access conduit. Releasing the button132 a causes the spring 162 to force the seal 160 back into its seatthereby automatically shutting the valve.

The evacuation valve 158 is of a different construction. In this valve158, the valve seal 170, in its off position as shown, seals the mouthof the evacuation conduit 152.

In operation, the seal 170 is moved under action of a plunger andevacuation button 132 b from the position shown to a position 170′ inwhich an end of a conduit 174, formed through the seal 170, aligns withthe central access conduit 154. At the same time the other end of theconduit 174 is aligned with the evacuation conduit 152 and evacuationcan be accomplished. By releasing the button 132 b, the spring 172biases the seal 170 back into its sealing position.

Assembly of this evacuation valve 158 is by inserting the entire valvemechanism into its valve bore and sealing a collar 176 in the bore.

As has been indicated with reference to FIG. 14, the cartridge 126 is ofthe disposable type and is intended for use only once. Accordingly theconsiderations of valve flushing (during cleaning) are not entirelyapplicable here.

In FIG. 16 yet another type of valve, which can be used as either anirrigation or an evacuation valve, is illustrated.

The valve, generally indicated as 180, is shown to include a hollowcylindrical valve body 182 which is sealed at its lower end by a valveseal 184 and at the other by an activator button 186. The activatorbutton 186 seals against the valve body with an O-ring 188 and isconnected to the valve seal 184 by means of a plunger 190.

To open the valve 180, the button 186 is depressed against the bias of aspring 192 to move the valve seal 184 to the position indicated inbroken lines. This opens a fluid path 194 between an opening 196 formedin the sidewall of the valve body and its lower end. Releasing thebutton 186 allows the spring 192 to force the seal 184 back into theclosed position.

One advantage of this valve is that it is very simple and inexpensive tomanufacture and can, therefore, readily be disposed of.

Finally, it will be apparent to anyone skilled in the art, that thesurgical instrument of this invention could be made from any suitablematerial. In the event that, the instrument is intended for single use,plastic material could be used. Alternatively, for reusable or reposableinstrument, the instrument can be made of a more durable material.

FIG. 17 is a perspective view of an endoscopic surgical instrument 200which is an alternate embodiment of the surgical instrument 20 describedabove. FIG. 18 is a partial sectional view of a portion of theinstrument 200 taken along the line 18—18 of FIG. 17 and FIG. 19 isanother view of the instrument 200 taken as indicated by the line 19—19of FIG. 17. FIG. 20 illustrates the retractable electrode assembly 202.When viewed together, FIGS. 17-20, illustrate the instrument 200including an endoscopic instrument 201, a retractable RF electrodeassembly 202, an continuous irrigation and evacuation assembly 203, aR.F. energy source 285, and a tissue impedance monitoring device 284. Itwill be appreciated that, although two retractable RF electrodes areillustrated and subsequently described, in alternate embodiments theretractable electrode assembly could have one or more than tworetractable RF electrodes. Also, although a bipolar retractable RFelectrode assembly is illustrated and subsequently described, it will beappreciated that a monopolar retractable RF electrode assembly could beused.

The assembly 203 includes a housing 210, an irrigation valve assembly214, and an evacuation valve assembly 220. The housing 210 includes anelongated portion 228 having a generally oval cross section. The portion228 includes a free tip end 230 and a secured end which is attached to ahandle portion 232. The portion 232 is held by the surgeon, and theportion 228 is surgically introduced into a body cavity (not shown) ofthe patient. A single access conduit 212 (a portion of which is bestseen in FIGS. 18 and 19) is formed between an inner surface of theportion 228 and the objects carried within the portion 228. The conduit212 is disposed along the entire longitudinal length of the portion 228and is functionally similar to the conduit 25 (FIG. 2) in that itpermits the irrigation and evacuation of fluids into and out from thebody cavity into which the portion 228 is inserted. The conduit 212 isopen at the tip end 230 and can be accessed, at its opposite end, via anaperture and associated closure 226 formed in the handle portion 232.The closure 226 is in the form of a tricuspid valve and is substantiallysimilar to the valve 31 illustrated and described above (FIG. 2).

The irrigation valve and the evacuation valve assemblies 214, 220 aresubstantially similar to the irrigation and evacuation valves 23, 24described above (FIG. 2). The valve assemblies 214, 220 operate in asimilar manner to valves 23, 24 (FIGS. 7, 8). Depressing the valveassemblies 214 or 220 permits the communication of fluid in a valvefirst conduit 216 (or 222) with a valve second conduit 218 (or 224).Each of the valve second conduits 218 and 224 are in fluid communicationwith the conduit 212 (in the same manner that the conduits 23 a, 24 aare in fluid communication with the conduit 25, FIG. 2). Thus, when thevalve assembly 214 is operated, irrigation fluid can be communicated tothe conduit 212 and out through the tip end 230, and delivered to thebody cavity. In a similar manner, fluids in the body cavity can beevacuated if the valve assembly 220 is operated.

The retractable electrode assembly 202 includes a means for guiding theangular orientation of the electrode or guide sheath 248, an endoscopesheath 238, a electrode movement mechanism 236, a tissue impedancemeasurement device 284, and a R.F. energy source 285. The sheath 248 isgenerally parallel to the scope sheath 238. The sheath 248 and thesheath 238 are each insertable into an opening of an insert flange 242,into the aperture of the handle portion 232 of the assembly 203. Thesheath 248 and the sheath 238 are insertable within the conduit 212 andare each of sufficient length such that when each is fully insertedwithin the conduit 212, each extends slightly beyond the tip end 230 ofthe cylindrical portion 228.

The endoscopic instrument or endoscope 201 is substantially similar tothe endoscope instrument described above, and can be any of a number ofdevices known in the prior art. An eyepiece 204 is shown attached to theendoscope 201. The endoscope 201 is slid into the scope sheath 238 untilthe eyepiece 204 engages a flange 240 which is attached to the sheath238. Thus, the endoscope 201, and the sheath 248 of the retractableelectrode assembly 202 are both insertable within the portion 228 of theirrigation and evacuation assembly 203.

Each of two RF electrodes 250 a, 250 b is sheathed within its respectiveguide sheath 248 a, 248 b. Although the illustrated embodiment depictstwo RF electrodes, it will be appreciated that the assembly 202 couldhave one or more than two electrodes. Each electrode 250 a, 250 bincludes a first or distal end 249 a, 249 b, a second, or proximal end247 a, 247 b, and a central portion (not shown) disposedly connectedtherebetween. A coating of insulation 246 is disposed onto the bareelectrode 250. The insulation coating 246 may be in the form of a tubeof material (such as teflon) heat shrunk around the bare electrode 250.Alternately, the insulating coat 246 may be powder deposited, usingvacuum deposition techniques, onto the bare electrode 250. In eithercase, nearly the entire length of the bare electrode 250 is covered bythe insulating coat 246.

The electrodes 250 a, 250 b have a generally constant diameterthroughout its entire length and are sized such that they can be slidwithin the sheaths 248 a, 248 b. That is, there exists a sufficientclearance (e.g. 0.005 inch) between the outside diameter of each of theinsulating coats 246 a, 246 b of the electrodes 250 a, 250 b and theinner diameter of the respective sheaths 248 a, 248 b. Each electrode250 a, 250 b is made from a superelastic metal material, e.g. typicallya Nickel-Titanium (NiTi) metal alloy. The guide sheaths 248 a, 248 b aremade from a rigid plastic or coated metal tubing which forms a rigidconduit that guides, i.e. deforms, the electrode along a predeterminedpath.

As best seen in FIG. 19, the electrodes 250 a, 250 b and theirrespective sheaths 248 a, 248 b are contained within the cross sectionalenvelope of the portion 228. Thus, the required incision into thepatient need only accommodate the cross sectional area of the portion228. The presence of the extendable electrodes does not increase thesize of the required incision. It should be also noted that eachelectrode 250 a, 250 b descends downwardly into the field of view of theendoscope 201. In this manner the surgeon is able to view the extensionof each electrode 250 a, 250 b beyond the end of the sheath 248 a, 248b.

The two electrodes 250 a, 250 b and their respective insulators 246 a,246 b are encased within their respective guide sheaths 248 a, 248 bwhich are encased within a plastic insulating covering 244. Theelectrodes 250 a and 250 b encased within the plastic covering 244 exitsthe housing 232 through the opening in the flange 242.

Each electrode 250 a, 250 b is in parallel electrical communication witha tissue impedance measuring device 284 and a R.F. energy source 285.The covering 244 enters the movement mechanism 236 through an opening260 formed in a sleeve 256 of the mechanism 236. The electrodes 250 a,250 b and their respective insulators 246 a, 246 b exit from thecovering 244 and each of the second ends 247 a, 247 b, of each of theelectrodes 250 a, 250 b are attached to connecting pins 272 a, 272 b,respectively. The connecting pins 272 a, 272 b are mounted at an end ofa plunger 264. Each connecting pin 272 a, 272 b is in communication witha wire 274 a, 274 b each of which passes through the plunger 264,through an opening 278, and into an insulated line 276 which isterminated in a plug 280 which is matingly engagable with a receptacle282 of the tissue impedance measuring device 284. The R.F. source 285 isin electrical communication with the impedance measuring device viaelectrical lines 283 a and 283 b. The source 285 and the impedancemeasuring device 284 are connectable in parallel in order to getrealtime impedance measurement of tissue engaged between the first ends249 a, 249 b of each of the electrode 250 a, 250 b.

The movement mechanism 236 includes a finger ring portion 252, and athumb ring portion 254. The finger ring portion 252 is a generally flatplate having finger loops 251 a, 251 b formed therein. A passage 262 isformed through the finger ring portion 252 such that the longitudinalaxis of the passage 262 is disposed between each finger loop and liescoplanar with the plane of each finger loop. The sleeve 256, and acylinder 258 are partially inserted into opposite ends of the passage262. The sleeve 256 has a passage longitudinally formed therein so as toreceive the covering 244. The cylinder 258 has a passage longitudinallyformed therein which is aligned with the passage of the sleeve. Theplunger 264 is slidable within the passage of the cylinder 258. One endof the plunger is attached to the thumb ring portion 254, and theconnection pins 272 a, 272 b are mounted to the other end of the plunger264. The outer surface of the plunger 264 is visible through an accesscutout 270 formed in the cylinder 258. In one embodiment, an indicatorpost 266 is attached to the outer surface of the plunger 264 and passesthrough the access cutout 270 to give an immediate visual indication ofthe position of the plunger 264 within the cylinder 258. In a preferredembodiment, the outer surface of the plunger 264 is scored with aplurality of indicator marks 268 to provide a visual indication of theposition of the plunger 264 within the cylinder 258, which correspondsto variable length of extension of each of the electrodes beyond theirrespective insulating sheaths.

In operation, the irrigation and evacuation valves, and the endoscopeoperate as described above. Regarding the retractable electrode assembly202, a free hand of the surgeon is used to operate the movementmechanism 236. The surgeon's fingers are engaged within the finger ringloops and the thumb is engaged within the thumb ring portion. The thumbeither pushes or pulls on the thumb ring thereby moving the attachedplunger 264 into or out of the cylinder 258 and the passage 262. As theplunger 264 moves each of the first ends 249 a, 249 b of each of theelectrodes 250 a, 250 b move because the connection pins 272 a, 272 bmounted to the plunger are attached to each of the second ends 247 a,247 b of each of the electrodes 250 a, 250 b. Thus, as the plunger movesin the direction of the arrow A, the central portions of each of theelectrodes moves within their respective insulators in the direction ofthe arrow B, and the first ends 249 a, 249 b move in the direction ofthe arrow C.

FIG. 21 illustrates the first end 249 of the electrode 250. The guidesheath 248 is formed with a bend at one end. The electrode 250 slideswithin the sheath 248 and exits the sheath 248 under the guidance of thesheath 248. The insulating cover 246 permits the easy'sliding of theelectrode within the sheath 248. Although a bend of 90 degrees isillustrated, it will be appreciated that a bend of any angle may beformed in the sheath 248 so as to guide the electrode 250 into a varietyof angular dispositions. It should be noted that the electrode 250 isbare in the vicinity of the first end 249. A predetermined length valueL, measured from the tip of the electrode to the end 255 of theinsulating coat 246, represents the length of the electrode 250 that isbare or uncoated. Typical values for L range from 0 to 3 cm.

The first ends of each electrode extends beyond its respective sheath248 by a length greater than the predetermined extension length L inorder to permit the bare electrode to penetrate a tissue portion up tothe full L value. Further, the first ends of each needle electrode areseparated by a predetermined separation width W (typically 0.1-2.0 cm)and each first end forms a predetermined angle θ with respect to thelongitudinal axis of portion 228. In the illustrated embodiment, theangle θ is 90 degrees. Typical values for θ range between 0 and 360degrees.

During surgical procedures, the tip end 230 of the portion 228 of theinstrument 200 is brought adjacent to a target tissue area of the bodycavity. The first ends of each electrode are extended beyond theirrespective sheaths such that each first end is embedded into the softtarget tissue area thereby defining a tissue portion engaged between theadjacent first ends of each electrode. The power source is energized andR.F. energy is transmitted from one electrode to the adjacent electrode.The energy transmission causes a coagulation of the tissue portionengaged between the adjacent electrodes and ablation of the targettissue.

Using the present invention, the surgeon can predict and control theamount of tissue ablation/coagulation with greater accuracy and safety.As described above, the spacing between the two parallel first ends ofeach electrode remains constant at some predetermined W value, e.g. 1.0cm. Also, the extension of the electrodes beyond the insulators at agiven angle, i.e. the depth. of penetration of each first ends of eachelectrode into the soft tissue portion, can be precisely controlled byobserving the indicator marks on the plunger. Predictable and precisetissue ablation is therefore possible with the present invention becausethe depth of each first end of each electrode in soft tissue can beprecisely controlled by the surgeon. That is, the surgeon can predict acylindrical zone of ablation by controlling the depth of the retractablefirst ends into the soft tissue portion. This precise depth controlenables the surgeon to predict the zone of ablation with greateraccuracy and safety than prior art non-retractable monopolar RF devices,or prior art laser delivery systems.

The cellular structure of body tissue contains water which is aconductor of electrical energy. Consequently, a portion of body tissuealso has an associated resistance or impedance value. In prior artmonopolar electrode devices, tissue impedance is difficult to measure.However, in the present invention, precise impedance measurement of thesoft tissue in the proximity of the bipolar electrodes is possible. Inthe present invention, during the tissue coagulation processsimultaneous measurement of the impedance of the tissue engaged betweenthe extended first ends of the electrodes signals the completion of thetissue coagulation process and provides assurance and confirmation tothe surgeon.

R.F. energy applied to the tissue engaged between the first ends of thetwo electrodes causes the tissue to coagulate which decreases the watercontent associated with the tissue. As the water content decreases theconductivity of the tissue decreases. For a constant R.F. energy, as theconductivity decreases the impedance (or resistance) associated with thetissue increases. The tissue impedance is highest when the tissue iscompletely coagulated, since coagulated tissue has a minimum amount ofwater content and current flow is blocked from one electrode to theother electrode. However, at the beginning of the ablation procedure,the tissue impedance is at a minimum because the water content of thetissue is at its highest level and the tissue is a good conductor andallows the maximum current to flow from one electrode to the other.During the ablation procedure, as the tissue coagulates the watercontent decreases and the tissue impedance increases. The tissueimpedance measurement device 284 can be designed to transmit an variablefrequency audible signal, i.e. a beeping tone, when the tissue impedanceis at its lowest value. As more tissue is ablated and as the tissueimpedance reaches its highest value the audible signal decreases infrequency. In the present invention, the tissue impedance is monitoredor measured on a relative basis. That is, the impedance measured ormonitored is the impedance of the tissue engaged between the two needleelectrodes.

FIGS. 22A through 22H illustrate alternate electrode configurations. Itwill be noted that the preferred embodiment of the present inventionincludes two electrodes with a θ of 90 degrees, and a L value of 0-3 cm,and a W value of 0.1-2.0 cm. It will be appreciated that a variety ofelectrode configurations, with associated L, W, and θ values within theabove specified ranges, are possible. However, it is generallypreferable to limit the total number of electrodes to six or less.

It will be noted that in the embodiments illustrated in FIGS. 22A-22C,22G-22H, the electrodes 250 are guided by the shape of the sheath 248.That is, the electrodes can be directed towards or away from each otherif the guide sheaths are angled towards or away from each other.Similarly, different θ values are possible if the sheaths are formedwith the appropriately angled bends.

However, in the embodiments illustrated in FIGS. 22D-22F, the sheathsare substantially straight and the electrodes themselves are bent inorder to direct them in certain orientations. This feature is moreclearly shown in FIG. 23 which illustrates a typical electrode having abend formed at the location depicted by numeral 257. When the electrodeis disposed within the sheath 248, the electrode 250 is in contact withat least one portion 259 of the inner surface of the sheath 248 becauseof the bend 257. When the electrode is extended beyond the sheath (shownin phantom lines), the electrode “flattens” within the sheath 248 whilethe electrode tip angles away from the sheath centerline in accordancewith the bend 257 formed in the electrode.

FIG. 24 illustrates a retractable electrode surgical instrument 300which is an alternate embodiment of the retractable electrode instrument200 (FIG. 17). The instrument 300 includes many of the same elements asthe instrument 200. These identical elements are identified with thesame reference numeral as shown in FIG. 17. In this embodiment, eachelectrode 250 a, 250 b is enclosed within a bendable guiding sheath 290a, 290 b. A guide wire 293 a, 293 b is disposed within each sheath 290a, 290 b and includes a first end 289 a, 289 b and a second end 291 a,291 b. Each first end 289 of each guide wire 293 is attached (e.g.welded or adhesively bonded) to an inner surface of a bendable orbellows portion 292 of the sheath 290 at a location proximate the openend of the sheath 290. Each second end 291 is attached to a lever orknob 294 which is mounted to an outer surface of a housing 291. Thehousing 291 is similar to the housing 232 and includes communicationports for an irrigation valve and an evacuation valve (neither shown).In operation, when there is no tension on the guide wires the sheathsare straight within the conduit, i.e. θ is 0 degrees. As the surgeonpulls back on the knob or lever, the wires are tensioned and the tips ofeach sheath is pulled back as illustrated until a desired θ value isobtained. In this embodiment, both the L and the θ values can beadjusted by the surgeon in situ.

With reference to FIG. 25, alternative embodiments for the electrodes ofthe present invention are shown. FIG. 25(a) illustrates an electrodeconfiguration similar to that shown in FIG. 22(a) except that two pairsof bipolar electrodes 350 a and 350 b are used. FIG. 25(a) shows theelectrodes 350(a) and 350(b) extending outward from sheaths 348(a) and348(b) at the distal end 349. Electrodes 350(a) are preferably eitherboth active or both passive, while the pair of electrodes 350 b encasedin sheaths 348 b have the opposite polarity. Alternatively, theelectrodes can have cross-polarity. The configuration shown in FIG.25(a) creates an approximately square or rectangular pattern ofelectrodes (depending upon spacing of 350 a and 350 b). The sheaths andelectrodes are shown bent at an angle of approximately 90 degrees, butother angles are useful as well, and are included in the spirit of theinvention. Although four sheath and electrode pairs are described withtwo as preferably receiving the active voltage/power and the other twoas ground, or i.e. passive, various other combinations are possible andincluded in the invention. A few of these possibilities are illustratedthrough use of FIGS. 25(b)-25(f) which show views of the ends of thesheaths and electrodes, omitting other details-for clarity. For example,FIG. 25(b) illustrates the arrangement of electrodes in FIG. 25(a). Withelectrodes 350(a) active and 350(b) passive, electric fields will extendbetween the two pairs approximately as shown by the dotted lines. Thetissue will be heated in a volume having a cross section which can beseen to be an approximate square or rectangular, depending on thespacing of the electrodes. The pattern for two electrodes (i.e. abipolar electrode) is shown in FIG. 25(c). The volume of tissue ablationis controlled by the depth of insertion of the needle electrodes intothe tissue.

Another alternative is shown in FIG. 25(d) in which two passiveelectrodes 350 a are used with a third active electrode 350 b, resultingin a generally circular cross sectional area of tissue ablation. Use ofmore electrodes will provide a more circular cross-section. As examples,FIGS. 25(e) and 25(f) are further variations which result in circulartissue ablation, both utilizing an active electrode 350 b surrounded bypassive electrodes 350 a. In all of the above described configurations,energy is passed from one electrode or electrodes to another electrodeor electrodes, through tissue in between, causing it to be heated. Thepreferred number of passive electrodes for circular tissue coagulationis in the range from 3 up to a maximum of 16. For optimal distributionof energy from the electrodes, it is preferred that the sum of areas ofthe active electrodes (designated as 350 b in FIG. 25) be approximatelyequal to the sum of the areas of the passive electrode(s) 350 a.

FIG. 26 shows an embodiment of the present invention providing acircular zone of coagulation of adjustable diameter. Active electrode350 b is surrounded in a circular pattern by passive electrodes 352.Electrodes 352 are superelastic metal “memory wires” such asnickel-titanium wires which are pretensioned to a bowed shape or angle.While the electrodes are inside of tubes 354, they are held in straightposition. When the electrodes are advanced outside of tubes 354, theyangle outward from the central axis of the supporting tube 354.Electrode 350 b is straight and preferably carries the active energyfrom the RF power source. In operation, the electrodes 352 and 350 b areall connected to the electrode moving mechanism 236 (FIG. 20) and movedin and out together. Alternately, electrode 350 b may be independentlymoved relative to the other electrodes 352, thus allowing forsignificant flexibility in adjusting the area of ablation orcoagulation. For clarity of illustration, only a portion of the tubesand electrodes is shown. The assembly is shown cut off at 355, butactually extends in length, the electrodes 352 and 350 b having aproximal end (not shown) which connects to the electrode movingmechanism, which in turn connects the electrodes to an RF energy source,for transmitting the power to the distal ends at 353. The dashed linesin FIG. 26(a) illustrate the movement of electrodes 350 b and 352, thecentral electrode 350 b being coaxial with the central axis andpreferably extending or retracting independently of electrodes 352. Asshown by the dashed lines, electrodes 352 may be extended outward andaway from electrode 350 b, the greater extension providing a greatercross-section of ablation/coagulation. The end of central electrode 350b is extended into the same plane as the ends of electrodes 352 forcoagulation of a volume of tissue having a circular cross sectionalarea.

Use of superelastic “memory wires” which exit the tubes 354 atpredetermined angles is preferred. Another method of angling theelectrodes outward is more clearly shown in FIG. 26(b) illustrating oneof the tubes 354 with an electrode 352 installed therein. Thepre-induced angle of electrode 352 causes it to bear against theinterior wall 356 and the rim 358 of the opening 360. The structure oftube 354 and electrode 352 combination (as shown in the figure) requirestube 354 to be constructed of an electrically insulating material sinceno coating is shown on electrode 352. Alternatively, or in addition tohaving tube 354 non-conductive, the electrode wires can be insulatedwith a thin non-conductive coating except for the end portion of thewires. In this manner, the only active portions of the electrodes arethose portions which do not have the non-conductive coating.

FIG. 26(a) shows a grouping of six tubes enclosing electrodes 352, andone tube with an electrode 350 b. Although six tubes 354 are shown, theinvention also includes other numbers of tubes, electrodes, andconfigurations, including such configurations corresponding to thepatterns illustrated in FIGS. 25(b) to 25(f). Arrangement of electrodesin a different pattern can be done to obtain coagulation of a volume oftissue having a rectangular, circular or other cross section. As analternate construction, the tubes 354 and 362 could be merged in onecontinuous piece of material with the required bores for guiding theelectrodes formed therethrough. Such an embodiment would look similar tothe cylindrical section of the embodiment to be described in FIG. 27.Note that the further the electrodes are advanced out of the tubes intobody tissue, the greater will be the volume of tissue coagulated, as thetissue provides a conductive path for the RF energy along the lengths ofthe electrodes inserted in the tissue.

Referring now to FIG. 27, there is shown an alternate embodiment foraccomplishing a similar purpose as presented in regard to the embodimentof FIG. 26. Instead of angular memory wire electrodes, all of electrodes366 are straight, and preferably constructed of superelastic conductivematerial, such as nickel titanium wire. Electrodes 366 as well ascentral electrode 368 are all guided by holes 370 through the firstsection 372 of the guiding structure 373. The structure 373 has aconical shaped end section 374, the narrow end of which is connected toa first end face 376 from which electrodes 366 emerge, and extends fromthe face 376 to a wide end 378 from which the central electrode 368emerges. The conical shape 374 interferes with the electrodes 366,deflecting them outward from the central axis 375 away from the centralelectrode 368. This provides a method for varying the angle ofdeflection from the central axis, and thereby achieving a larger orsmaller cross section of tissue coagulation, with end sections usingdifferent angles for the conical shape.

As with the embodiment of FIG. 26, the further the electrodes 366 areprotruded from the casing 372, the farther they extend from the centralelectrode 368, creating a larger area of ablation/coagulation. Theelectrodes' proximal ends at 380 are to be connected to an electrodemovement mechanism such as 236 shown in FIG. 20.

FIG. 28 illustrates a connecting cable assembly 394 for an RF generatorsystem utilizing the apparatus above described, and additionally has thefacility for providing either monopolar RF power to the electrodes fortissue cutting/coagulation or bipolar power for coagulation procedures.The use of the monopolar RF power between two electrodes in closeproximity has not been addressed in the prior art, and will be shown tohave significant advantages. In the prior art, monopolar electrodes havebeen used with a patient return pad to complete the electrical path.Monopolar applications use higher RF power, typically for tissue cuttingand coagulation. The use of patient return pads creates an electricalpath from the active monopolar electrode to the return, pad. This paththerefore tends to be relatively long, unpredictable, and unsafe.

The single connecting cable system shown in FIG. 28 allows the surgeonto use one instrument either in monopolar or bipolar mode. The singlecable system also eliminates the need for patient return grounding padsand the associated risk of “stray currents” and adjacent tissue damage.In FIG. 28, cable assembly 394 includes two bipolar cables 396 and 398having banana plugs 400 and 402, each of the cables 396 and 398 leadingfrom an interconnection block 404. The banana plugs 400 and 402 are forinterconnection with bipolar receptacles 406 and 408 of RF generator410. There is a monopolar output cable 412 leading from theinterconnection block 404 with a monopolar plug 414 for interconnectionwith monopolar receptacle 416 of the RF generator 410 (receptacle 416 istypically labelled “Foot Control” in commercially available RFgenerators). A return path cable 418 is shown leading from theinterconnection block 404, and has a connector 420 for mating withreceptacle 422 of the RF generator 410 (receptacle 422 is typicallylabelled “Patient Return”). The function of the interconnection block isto join the bipolar cables 396 and 398 to the monopolar output cable 412and return path cable 418. The block 404 then connects the resultant twowires to an output cable 424 which passes the RF power through aconnector assembly 425 to electrode movement mechanism 236 which in turnconnects the power to the electrodes.

The RF generator 410 is a standard energy source in the industry, andhas facility for switching the power output either to the higher powerlevel for use in the monopolar mode for cut/coagulation, or to the lowerpower bipolar mode for coagulation. FIG. 28 also shows a standard footpedal 426 interconnected with the RF power generator 410 through cable428 for turning the RF power output of the generator 410 off or on incut or coagulation mode.

The above described cable assembly is used with the above describedendoscopic surgical instrument to allow either monopolar or bipolarpower to be supplied to the electrodes without having to manuallyconnect and disconnect separate cables to RF generator 410.

The convenience of being able to select either monopolar or a bipolarenergy for application to a single electrode assembly gives a surgeonsignificantly enhanced surgical capability and convenience in themonopolar mode, ablation and removal of tissue is possible, and in thebipolar mode, coagulation is possible, allowing the surgeon to makedecisions after insertion of a single electrode apparatus. Previously,use of electrodes in bipolar and monopolar modes required time consumingremoval of electrodes and complete change of operating procedures andinstrumentation.

Method for Removing Uterine Fibroids

Over thirty percent of women between 30 and 50 years of age have uterinefibroids, which can cause abnormal bleeding and associated problems.There are three major kinds of fibroids:

(1) subserosal fibroids which are located outside the wall of theuterus; (2) intramural fibroids which are located inside the uterinewall; and (3) submucosal fibroids which are located outside theendometrium. The majority of fibroids needing treatment to preventabnormal bleeding are the submucosal type. Treatment options for uterinefibroids have included drug therapy and surgical treatment. Drug therapyis used to shrink the fibroid, but is expensive and fibroids return totheir original size within four months of ceasing use of the drugtherapy. Surgical treatment such as myomectomy or hysterectomy involvesignificant hospital stay and recovery time as well as high costs.Alternative treatments therefore are preferred to drug therapy orsurgical treatment.

Laparoscopic myoma coagulation is used for the treatment of subserosaland intramural fibroids. Submucosal fibroids cannot be treatedlaparoscopically due to the need for an internal incision and closure ofthe uterine wall. Laparoscopic coagulation uses a Nd:YAG laser orbipolar/monopolar electrosurgical electrodes to shrink the fibroids.

The prior art use of R.F. needle electrodes for laparoscopic coagulationhas been limited to a single monopolar electrode or to a pair of bipolarelectrodes for laparoscopic treatment of uterine fibroids because theprior art electrodes can only be used along the axis of visualization ofthe laparoscope. Additionally, the prior art single monopolar or pair ofbipolar electrodes have provided only a limited area of tissuecoagulation. The electrodes of the present invention as described above,provide a larger zone of coagulation, and may be used for laparoscopicor hysteroscopic treatment of uterine fibroids. The needle electrodesdescribed herein may be introduced to the sidewall of the uterus at anyangle to the axis of visualization of the hysteroscope.

The flexible needle electrodes of the present invention allow the angleof entry to tissue (relative to the axis of the probe) to be adjusted toany angle. Moreover, the use of multiple electrodes with an adjustableangle of entry to tissue, allows a larger sized area of tissuecoagulation, including areas which have greater area than the size ofthe probe which guides the needle electrodes to the tissue insertionsite.

The present invention treats uterine fibroids with hysteroscopicmyolysis. The uterine fibroids are first identified using hysteroscopy,endovaginal ultrasound, computerized axial tomography, or MRI to allowvisualization of the interior of the uterine cavity. By such imaging ofthe uterine cavity, the size, shape and position of any fibroid can bedetermined. Hysteroscopic myolysis can then be performed using amonopolar needle electrode, or one of the bipolar needle electrodeconfigurations of the present invention as above described. To protectthe rectum, bladder and blood vessels of the uterus, vaginal ultrasoundis used to determine the fibroid's posterior surface prior to insertionof the electrode(s). The R.F. needle electrodes are then insertedthrough an operating hysteroscope. The electrodes can then bemanipulated and inserted in the fibroids to the desired depth underdirect visualization of the hysteroscope, and the area surrounding theelectrodes may be coagulated. By repeatedly puncturing the fibroid withthe needle electrodes, the entire fibroid can be coagulated.

This disclosure addresses uterine fibroid treatment in particular.However, the method described can be used for ablation/removal of anysoft tissue, such as breast; liver, colon, and prostate tumors/growths.FIG. 33 shows an alternative endoscopic surgical instrument 431. An RFelectrode 432 with a field enhancement tip 476 is installed in analternative style of retractable RF electrode assembly 430. Theelectrode 432 can also be used with the assembly 203 of FIG. 17 or anyother compatible assembly structure. The apparatus of FIG. 33 includesan outer housing 434 that has a large outer sheath 436 extending fromthe connection end 438 to the distal end 440, the outer sheathenlargened slightly at 442 over the length of a perforated end section444. The housing 434 has a handle grip 446 and a suction port 448, theport 448 terminating in a valve 450 followed by a Luer connector 452 forconnection to a suction line (not shown). The housing 434 has a housingconnector receptacle 454 for engagement with a mating sleeve 456, thesubstantial portion of which is inside receptacle 454 and not visible asillustrated. The mating sleeve 456 is part of a conduit housing andelectrode movement assembly 457. An inner sheath 460 is shown insertedthrough the outer sheath 436 and terminating at end 462. The matingsleeve 456 and receptacle 454 secure the assembly 457 to the housing434. The block 458 in combination with guides 464 and 466, RF connectorblock 468, spring 470, thumb ring 472, and end plate 474 provide formovement of the RF electrode 432 position. In particular, the distanceof the tip 476 can be adjusted relative to the end 462. The block 458also has irrigation port 478 attached, having a valve 480 and Luerfitting 482 for connection to an irrigation fluid supply line (notshown).

The inner sheath 460 is a cylindrical tubing with two annular openingstherethrough including a first opening 484 extending through the sheath460 and from end 486 through the plate 474, guide 464, and through thehousing 458. The opening 484 is for insertion of the endoscope 489 probe488 extending from the telescope 490. The plate 474 has a connectorreceptacle 492 which receives an endoscope mating portion 494, and locksthe telescope in place with the assembly 457.

Irrigation fluid going through port 478 passes into a passage in block458 and into bore 484 to pass through clearance between the bore 484 andthe endoscope probe 488 to exit out the end 462 of sheath 460. Debris tobe evacuated is pulled through holes 492 and passes along clearance 494between the sheath 460 and the bore 436 to exit via a hole in the bore436 to pipe 448.

The electrode 432 has an elongated stem 496 that is inserted through thesecond annular opening 498, through the inner sheath 460 and block 458to exit at face 500. The stem then enters connector block 468 where anRF connection end of the electrode stem is connected by a spring loadedlatch mechanism 504 and placed in electrical contact with the center pinof RF connector plug 502. The assembly 430 as shown in FIG. 33 is one ofa number of existing assemblies that are used for inserting an endoscopeand an RF probe into a patient, including assemblies with electrodemovement mechanisms such as 236 in FIG. 17. The present inventionincludes RF electrode 432 having a novel field enhancement tip 476, thevarious embodiments of which will be fully explained in reference to thefollowing figures of the drawing.

FIG. 33 also illustrates the use of the apparatus in either monopolar orbipolar operation. For the purpose of this discussion, monopolar mode isdefined as that mode of operation using an external body pad such as 802in the electrical return path to the RF generator. Bipolar operation iswhen the return path is through a conductive element located relativelynear the electrode tip that is connected to the RF generator activeside. Generally, such a conductive element for bipolar operation will bewithin the patient's body. For the following disclosure, the electrodetip 476 of FIG. 33 and the conductive element used to receive RF energyfor the return path can be of any electrode type, including one or moreneedle tips, rollers, loops, disks, etc. Examples of needle tips arethose of FIGS. 17-27, and loops and rollers are exemplified in FIGS.44-61. The preferred embodiment for bipolar operation utilizes theendoscope probe outer sheath 436 as the return electrode. In this case,the sheath is constructed of an electrically conductive material, andconnection to the RF generator is made by any of various ways known tothose skilled in the art. The preferred method of connection will bedescribed in the following detailed description. Alternatively, anyportion of the sheath, or any conductive element can be positioned at ornear the distal tip end of the probe to function as a return electrode,and electrical connection can be made by a conductor alongside orinterior to the probe. For example; the perforated section 444 could beconstructed of electrically conductive material to serve as a conductiveelement for the return path, with the remainder of the housing 434constructed of insulative material. In such a case, a separateconductive line would have to be used to connect the section 444 to aconnector for attachment to a line from the RF generator passive side810.

FIG. 33 also illustrates the use of a fluid 828, which can be eitherisotonic or non-isotonic, for use in either monopolar or bipolar mode,the use depending on the system requirements which will be discussed inthe following description. Operating the apparatus of FIG. 33 involvesbringing the electrode tip 476 into contact with a tissue surface 800.In the case of monopolar operation, a conductive return pad 802 isplaced on a body exterior 804 area in closest proximity to the tip 476,and is connected electrically as indicated by line 806 to thereturn/passive side 810 of an RF generator 812. The line 806 is shownpartially in dashed lines 808 to indicate that it is an alternative to aconnection for bipolar operation.

The preferred bipolar connection, applicable for example when theendoscope probe outer sheath 436 is used as the return electrode, isindicated by line 814 to the conductive housing 458 and outer sheath 436by way of the Luer fitting 452, valve 450 and line 448, all constructedof electrically conductive material. Various ways of making electricalcontact to the sheath 436 will be apparent to those skilled in the art,and these are indicated in the spirit of the present invention. Thepreferred method of making electrical contact from the passive side ofthe RF generator to the Luer fitting 452 is through use of an adapter816. The adapter 816 provides passage of fluid from Luer connector 452to a Luer type connector 817. A lever 819 is shown, indicating theoption/alternative of having a fluid valve in the adapter 816. Theadapter 816 has a banana plug 821 attached for connection to areceptacle 823 providing connection to line 814 to the passive side 810of the RF generator 812.

The active side 820 of the RF generator is preferably connected to theprobe 476 as follows. The electrical line 818 carries the RF energy fromthe supply 812 active terminal 820 of RF generator 812 to connector 502,from which the RF energy is carried to the tip 476 by way of aconductive center conductor in the insulated electrode stem 496, whichwill be shown in detail in FIGS. 34A-34C. The mating connector 503,connecting line 818 to connector 502 is shown in dashed lines so as notto confuse it as part of a spring loaded locking device. 504 whichextends to a groove in the electrode connective end to captivate theelectrode in place. Such grooves are noted as 835 in FIG. 35B and 861and 863 in FIG. 34D. The details of such a captivation device andequivalents will be understood by those skilled in the art.

An electrode embodiment using two electrode tips for bipolar operationis shown in FIG. 34D. In this case, one of the tips, for example 848,connected to connector 862 receives energy from the active side of theRF generator through line 818 and connector apparatus 502 and 504 asdescribed above. The other electrode 854, connected to connector 864 ispreferably connected to the passive side 810 of the RF generator by wayof a second line and connection system similar to line 818 andconnection apparatus 502 and 504. This is indicated symbolically in FIG.33 by dashed line 819. The details of the dual electrode of FIG. 34Dwill be fully described in the following text in reference to thefigure.

In monopolar mode, the RF energy is conducted by the tissue 822 betweenthe tip 476 and the return pad 802 as indicated by the dashed lines 824.Although the greatest tissue heating occurs near the tip 476 asindicated by the closer spacing of the lines 824, all of the tissuebetween the tip 476 and pad 802 is heated to some degree. This is adisadvantage of the monopolar mode when the tissue requiring treatmentis localized to a relatively small surface area, because healthy tissuecan be damaged by stray RF current to some degree. In monopolaroperation, a fluid 828 can be applied for improving contact between theelectrode tip and the tissue surface 800. This fluid can be eitherisotonic or non-isotonic. Isotonic fluid is defined as electricallyconductive fluid such as a 0.9% saline solution.

In those cases where the tissue area to be treated is localized near thesurface 800, a bipolar connection of the apparatus is preferred becauseit confines the RF energy to a smaller area. As described above, thepreferred arrangement for bipolar operation is accomplished byconnection of the passive terminal 810 of the RF generator 812 to themetal housing 434 by way of line 814, connector 823, adapter 816 andvalve 452 which makes electrical contact with housing 434. With thisbipolar connection, the RF energy passes between the tip 476 and thehousing 434, as indicated by dashed lines 826, the field concentratednear the perforated end section 444 of housing 434, i.e., the tip of theresectoscope.

Due to the uncertain electrical connection between the end section (tipof resectoscope) 444 and the tissue surface 800, a preferred method ofoperation in this bipolar arrangement uses a fluid 828 applied betweenthe tissue and end section 444. This fluid can be either isotonic ornon-isotonic, but the preferred embodiment uses an isotonic fluid, andthe preferred isotonic fluid 828 is a 0.9% saline solution. The isotonicfluid 828 conducts RF energy from the tip 476 to the tissue 800 and fromthe tissue 800 to the sheath 436 of housing 434, and enhances the tissueheating by providing a more conductive electrical path from the tip 476to the RF generator.

FIG. 34 shows an electrode 506 according to the present invention, withan elongated stem 507 allowing use with the device of FIG. 33 or similarcommercially available device. Other forms of stem or i.e. connectiveline to electrode movement means of different design are also includedin the present invention, such as an elongated flexible shaft for usewith the device of FIG. 17. A novel feature according to the presentinvention is the incorporation of an RF field enhancement tip in theform of a roller 508 having narrow edged energy directors 510. Theroller bar 508 is rotatably mounted on a straight, uninsulated portion512 of the loop 509 joining conductive branches 513 and 514.

The electrode stem 507 has a conductive connecting end 516 with a notch518 for connection by the means 504 referred to in the discussion ofFIG. 33, for making contact with plug 502. Plug 502 in turn is connectedto an RF power supply. In the various figures of the drawing, theelectrode tips are all drawn showing a wire or wires leading from them.For brevity, the figures are drawn in simplified schematic form. Inaddition, two wires from a single tip are assumed to be connectedtogether such as the branches 513, 514 in the tip of FIG. 34. Inoperation, the wires (branches) are connected to a stem and then to anRF power supply. In bipolar mode, two electrodes are used, and are shownin the figures with an independent wire leading from each of theelectrodes. One of these wires is to be assumed connected, in operation,to one side (first side) of an RF power supply, and the other is to beassumed connected to the other side (second side) of the RF supply.Referring again to FIG. 34, a single conductor 520 extends from theconnecting end 516 to junction 522 where the conductor joins the twobranches 513 and. 514 which are joined by the straight uninsulatedportion 512. The conductor 520 and branches 513 and 514 are covered withinsulation 524. The straight portion 512 is not insulated in order tomake contact with the roller 508. A metal guide sheath 526 covers theinsulation 524 over a portion of the conductor 520 to provide guidanceand rigidity to the electrode 506 as it is forced by the movement ofblock 468 to move in the second annular opening 498 of the inner sheath460 of the resectoscope as shown in FIG. 33.

The electrode stem 507, as mentioned above, can be whateverconfiguration is required to conform to the particular electrodemovement device used. FIGS. 34A, 34B and 34C show an alternative stemdesign 830 that includes a telescope guide 832 and insulation covering834 over the conductor 836, both constructed of electrically insulativematerial. The proximal end 837 has a connector plug 839 for mating witha corresponding receptacle connected to a line for connecting to aterminal (preferably active side) of an RF signal generator. The designof FIGS. 34A-34C does not use a bare metal sheath over the insulation834. If a metal sheath is required, such as for providing rigidity tothe stem 496, it is preferably also covered with insulative material.The electrode configuration of FIGS. 34A-34C allows the electrode and atelescope to pass through a single bore in an endoscope probe housing,such as 434 in FIG. 33. This is illustrated more clearly in FIG. 34E,showing the housing 434 with the alternative stem design 830 and anendoscopic telescope 838 guided by the non-conductive saddle shapedtelescope guide 832. The purpose of the insulative covering 834 and thetelescope guide 832 constructed of electrically insulative material isto give assurance that all of the RF energy is transmitted at theelectrode tip, and that no RF energy can pass/leak directly from theconductor 836 to the endoscope housing 434 in which it is positioned,thus minimizing RF energy loss. The saddle shaped telescope guide shownin FIGS. 34A-34C is given by way of example and as the preferredembodiment. Other telescope guide structures will be apparent to thoseskilled in the art and are included in the spirit of the presentinvention. For example, the guide could be a 360° C. circular loop ofinsulative material, etc.

The tip 840 of FIG. 34A is a wire loop for cutting tissue. The crosssection and surface of the wire can be configured in any manner. Forexample, the cross section can be circular, rectangular, triangular or aflat ribbon. The surface finish of the wire can be serrated, knurled,slotted, etc.

The roller tip 842 of FIG. 34B can be used for coagulation, and the tip844 of FIG. 34C demonstrates the use of protrusions, i.e. energydirectors on the roller, having extremities of smaller area providing RFfield enhancement with corresponding higher power density for vaporizingtissue.

FIG. 34D illustrates an electrode apparatus 846 having two tips forbipolar operation. A first electrode tip 848 makes electrical contact toa first conductor 850 of stem 852. A second tip 854 makes electricalcontact with a second conductor 856 of stem 852. The stem has insulation858 for electrically isolating the first and second conductors from eachother, and from surrounding apparatus including the endoscope innersheath 460, for example of FIG. 33, when installed. The proximal end 860of the electrode apparatus 846 has connector elements 862 and 864 formaking electrical contact to corresponding mating connectors toelectrical lines leading in the active and passive sides of an RFgenerator. The details discussed above relating to the construction ofelectrode devices in FIGS. 34A-34E apply as well to electrode deviceswithout the telescope guide, such as the electrode device shown in FIG.33. The tips involving rollers and loops shown in FIGS. 34A-34E are alsogiven by way of example, and other types of tips are also included inthe spirit of the present invention. For example, a single or multipleneedle probe could be used. The dual conductive support such as 850 and856 and corresponding items in FIGS. 34A-34C are also given as examples,and other constructions which will be apparent to those skilled in theart are also included in the spirit of the present invention. Forexample, if a needle tip is used, only a single conductive line would berequired to support it, rather than the two lines such as 850 used tosupport a roller or loop.

An alternate feature involving the electrode 506 is shown in FIG. 35illustrating portion 525 of FIG. 34 showing an electrode tip to shaftconnection 527 that when incorporated allows an RF electrode tip module529 to be removed from a stem 531 and replaced. The electrode tipconnector as illustrated in FIG. 35 includes a plug 533 having a tip 535that is forced into slot 537 in the wall receptacle 539. The tolerancingof the bore 541 of the thin walled receptacle 539 relative to thediameter 543 and size of tip 535 of the latch 533 allows the receptaclewall, constructed of resilient materials, to yield to the entrance ofthe plug and retain the tip in the slot by resilient receptacle wallpressure. An alternate tip module 544 and mating stem 546 are shown inFIGS. 36 and 37. The tip module 544 has a straight plug 543 whichengages in a leaf spring connector 550. The connector 550 is formed byboring a hole 552 in the conductor 520, forming slots 554 in the wall556 to create leaf springs 558 which are compressed and usually heattreated. A spring latch 560 is mounted to the metal sleeve 526 and has ahooked end 562 for engagement in the y-space 564 of the tip module 544,as shown in

FIG. 37 to retain the tip 544 in engagement with the stem 546. The arm561 is a flexible resilient member allowing the latch 560 to bepositioned as indicated by the dashed outline 563 so as to provideclearance for the plug 543 to engage in the connector 550, and to thenallow the loaded end 562 to enter the y-space 564. Other means forconnecting the tip module to the stem will be understood by thoseskilled in the art, and are also included in the present invention. Theprimary benefit of the tip module is the ability to mount any of avariety of tips, e.g. roller bar, cutting loop, vaporizing loop, etc.without having to also replace the stem. This results in a costreduction, and offers greater variety during surgery. Any of the varietyof tips described in this specification can be used with the tip module.The tip 548 shown in FIGS. 36 and 37 is a roller tip. FIGS. 38-40illustrate the use of a roller (FIG. 38), cutting loop (FIG. 39) anddual rollers (FIG. 40). Although FIG. 40 as well as other figures of thedrawing show only two electrode tips per electrode or tip module, thespirit of the present invention includes any number of electrode tipsper electrode or tip module. For example, the rapid removal of largerareas of tissue may be facilitated by an electrode with a larger arrayof tips.

The tip modules can also be used in pairs for bipolar operation. Forthis purpose two modules can either be mounted/fabricated as anintegrated unit and connected to a corresponding dual stem to transferelectrode movement and RF power to the tips, or each module can beseparately attached to an independently controlled stem.

Referring now to FIG. 41, the roller 508 and conductor portion 512 aremore clearly shown in the cross-section 31—31 of FIG. 34A. The roller508 is shown to have a bore 564 therethrough for passage of theuninsulated conductor portion 512, which is bent at each end to form theconductor of branches 513 and 514 covered with insulation 524. Theroller 508 has energy directors 566 with reduced area narrow edgedsurfaces 568 created by the formation of V shaped grooves 570 in theroller 508. The narrow surfaces 568 concentrate RF electromagneticfields, increasing the RF power density so as to provide tissuevaporization. The benefit of the high energy density is that tissue canbe vaporized in the localized, controlled area of the roller, and at thesame time the resulting underlying tissue is subjected to enough heat tocause tissue coagulation. The significant field enhancement provided byan electrode tip with energy directors having reduced area extensionscompared with a prior art electrode design is illustrated in FIGS. 42and 43. The sharp edges 572 of the electrode 574 of FIG. 42 generatesvery high RF field concentration. The prior art device 576 of FIG. 43 bycomparison generates lower power density. The RF energy is slightlyconcentrated only at the edges 578 of the roller.

The rolling action of roller 508 provides a benefit that is illustratedin FIG. 44, which shows the roller 508, part of branches 513, 514 andportion 512. The roller 508 is pressed against tissue 580, a first layer582 of which is vaporized as indicated by arrows 584. The tissue layer586, exposed due to vaporization of layer 582, is subjected to enoughheat for coagulation. The rolling action of roller 508 indicated byarrows 588 helps to overcome the impediment of sticking tissue. As theroller is pulled in the direction of arrow 590 over the tissue 580, afresh roller surface is continually presented at 592. The upward thrustof the roller at point 594 encourages the coagulated, sticking tissue586 to pull away from the roller. The sticking of tissue to the rolleris also controlled by the fact that since the heat is generated in thetissue, the roller portion 596 that is not in contact with the tissuehas some time to “cool” before coming in contact with the tissue againat point 592. The rolling action therefore results in a greater rate ofvaporization, and reduced tissue sticking.

The present invention also includes selected tip surface material tominimize sticking of tissue. The preferred embodiment is a gold surface,but other materials for reducing sticking are also included such assilver.

The roller 508, through operation of the electrode in back and forthmovement using a device such as that of FIG. 33, can be passedrepeatedly over a selected tissue area to vaporize successive layers oftissue that need to be removed. The use of the electrode as illustratedin FIG. 44 is in what is called a monopolar mode, where RF voltage isapplied between the electrode roller and a return plate (not shown)which is normally attached to an exterior body surface in closestproximity to the roller 508.

The roller configuration of FIG. 44 is an example and preferredembodiment of the present invention. Other electrode tip designs thatprovide field enhancement through provision of energy director locationsof reduced area will be apparent to those skilled in the art, and theseare included in the spirit of the invention. Examples of other electrodetips that provide field enhancement are shown in FIGS. 45-53, FIG. 45shows a ridge 598 configured in the shape of a helix. FIG. 46 shows thehelix of FIG. 45 with grooves 600 further reducing the energy directorarea. FIG. 47 illustrates narrow extensions 602 that provide fieldenhancement by causing field concentration on the bottom 2 or 3extensions in contact with the tissue. FIG. 48 is a series ofindependent, non-connected disks 604 threaded on the straight portion ofwire 606. FIG. 49A shows independent disks 608 on a conductor 610 ofcurved shape. The roller loop electrode of FIG. 49A is an example of theflexible use of disks to create an electrode tip. A wide range of loopshapes are possible to form a “custom” electrode shape for a particularpurpose. Examples of custom shapes are shown in FIGS. 49B, C and D. Asin the other figures, the two leads, such as 611 and 613 of FIG. 49B arepreferably connected, resulting in a more mechanically supportedstructure. Application of RF energy to either or both of leads 611and/or 613 will empower the electrode. Combination of these or similarelectrodes with each other, or with other types of electrodes in eithermonopolar or bipolar arrangements are all included in the spirit of thepresent invention. FIG. 50 illustrates forming reduced area energydirectors 612 from a cylindrical shaped roller or helical profileroller.

Although the roller feature has advantages as discussed above inreference to FIG. 44, combined vaporization and coagulation can beachieved with non-rotating electrode tips. Electrode configurations thatare non-rotating, but incorporate the RF field enhancement feature arealso included in the spirit of the present invention. For example, FIG.51 shows an electrode configuration that is inherently non-rotating, butcan be fabricated with surfaces of the appropriate area formed as turns614 of the conductor 616. Other examples of non-rotating vaporizationtips would be structures such as the rollers of the various figuresdescribed above if the rollers were soldered or otherwise attached in anon-rotating manner. And, of course, a flat plate configuration with Vshaped grooves or other profile on the bottom could be designed tovaporize tissue. These various alternative designs are all included inthe spirit of the present invention.

FIG. 52 illustrates a further alternate embodiment wherein the electrodehas two roller electrodes 618, 620, however the electrodes can be of anytype, such as those discussed above in the various figures. Since the RFvoltage to each tip 618, 620 is substantially the same, the area ofvaporization is approximately doubled. Since the electrode's energydirector tips are arranged in staggered fashion, as the electrode ismoved, an area is vaporized and coagulated by one tip and then vaporizedand coagulated again by the other.

FIG. 53 shows an embodiment of the present invention using two tips inmonopolar mode wherein a first electrode tip 622 in the shape of asingle wire loop is operated in combination with a second tip 624 havinga larger surface area. The very limited small area of the wire tip 622provides an intense field pattern, resulting in a high power densitythat cuts tissue. The sharp cutting action, however, leaves the tissueexposed and bleeding. The function of the second tip 624 is to followthe first tip 622 and coagulate the exposed tissue. A coagulating tiphas surface area(s) that are larger than those configured forvaporization. Specific dimensions for the tips can vary depending on thedesired tissue effect. The differences in tip surface constructionbetween a tip designed for coagulation and one designed for vaporizationcan be readily determined through experiment by one skilled in the art,as may be necessary in the designs where the quantitative difference isnot obvious from the disclosure of the present invention. Such a case,for example, would be a coiled electrode tip where the wire diameter andspacing would determine whether the tip cuts or vaporizes or does bothsimultaneously. The coil shown for tip 614 of FIG. 51 if designed forcoagulation would therefore have larger dimensions than a similar coilfor vaporization, the dimensions including wire diameter, spacing, etc.,resulting in the required larger area. The combination of a cutting loopelectrode tip followed by a coagulating tip is a novel feature of thepresent invention.

Other combinations of tips in a monopolar mode will be apparent from theabove disclosure to those skilled in the art, and they are also includedin the spirit of the present invention. Various other monopolarembodiments will be described in reference to the following figures ofthe drawing.

Alternative embodiments of the present invention also include bipolaroperation, where the electrode (or electrodes) receiving RF of onepolarity (exp. active) are spaced more closely to the electrode (orelectrodes) of the opposite polarity (return) than is the case inmonopolar operation. In monopolar operation, the return electrode is aconductor of large surface area attached to the patient's body exterior,and serves as a “return electrode” from the active electrode. Any of theabove electrode tips discussed in relation to monopolar operation canalso be used in bipolar operation, an example being shown in FIG. 54wherein a side view is given of two electrodes 626, 628 with roller tips630, 632. One of the electrodes, for example, 626 is connected to theactive side of the RF power supply and the other 628 is connected to thereturn side. An advantage of using the bipolar configuration is that theclose spacing of the two electrodes confines the RF power to a smallerarea of tissue. Instead of the RF fields spreading outward andterminating/returning through a body plate, the field is confinedbetween the two electrodes as illustrated in FIG. 54, where the electricfield pattern is predominantly as shown by the dashed lines 634 passingthrough the tissue 636 near the surface 638. The higher conductivity ofthe tissue 636 tends to confine the RF fields primarily in the tissue636. The two electrodes can be attached mechanically as at 640, or inother ways known to those skilled in the art, or they can bemechanically independent enabling connection to the proximal connectorof the device.

Other bipolar arrangements are shown in FIGS. 55-60. FIG. 55 shows twocoils of wire interwound and spaced apart with insulative material 642such as ceramic. As an example of operation, first coil 644 could beconnected to the active side of an RF supply, and the second coil 646(insulated from the first coil) would be connected to the return side ofthe RF supply. The present invention also includes configurationswherein the two electrodes are not of the same configuration. This isillustrated somewhat schematically in FIG. 56 where one tip 648 is athin wire loop, and the other tip 650 is a roller bar. In this case, forexample, the thin loop could be used for cutting, and the roller barcould be designed for either coagulation, or simultaneous vaporizationand coagulation, depending on the design of the roller surface asexplained above. FIG. 57A is an arrangement of a thin wire loopelectrode 652 for cutting, which could, for example, be connected to theactive RF supply side, and a thicker loop electrode 654 for coagulationwhich would be connected to the return RF supply side. FIGS. 57B-57Eshow various electrode cross sections, such as noted by cross sectiondesignations “AA” and “BB” in FIG. 57A. In FIG. 57A, either of theelectrodes 652 and/or 654 could be of any desired cross section, such asthe triangular shape in FIG. 57B, the flat shape of FIG. 57C, or roundor rectangular/square in FIGS. 57D and 57E respectively. Other crosssections are also included in the spirit of the invention. In addition,the cross section of FIGS. 57B-57E and other cross sections apply to theother wire electrodes in this specification, such as those in FIGS. 39,51, 56 and 59.

FIG. 58 shows two loop shaped electrodes 656 and 658, each of which hasa plurality of narrow edged roller disks 660, each disk independentlyfree to rotate on the associated wire loop 662. The narrow edged rollerdisk electrodes 656, 658 are suitable for vaporization-coagulationeffect.

FIG. 59 illustrates the use of two cutting loop electrodes 664, 666 andFIG. 60 shows a combination of a roller disk electrode 668 forvaporization and a roller electrode with a plain surface 670 forcoagulation.

FIG. 61 is an example of an integrated bipolar electrode using rollerdisks. Conductor 672 is for connection to one side (active or passive)of the RF supply, and conductor 674 is for connection to the opposite(passive or active) side. Conductor 672 joins arms 676, 678 whichsupport coaxially aligned tubes 680, 682 upon which are rotatablymounted disks 684, 686.

Insulative tubes 688, 690 are installed inside tubes 680, 682, throughwhich passes conductor 692 joined to conductor branches 694, 696 furtherjoined to conductor 674. The insulative tubes 688, 690 have insulativeflanges 698, 700 for the purpose of electrically isolating roller disk702 from conductor tubes 680, 682. Disk 702 is rotatably mounted onconductor 692. In operation, energy passes between disk 702 at one RFpolarity to disks 684, 686 at the other polarity, heating tissue lyingwithin the electromagnetic field formed therebetween.

In addition to the above combinations of electrodes in bipolar andmonopolar modes, other combinations will be apparent from the abovedisclosure to those skilled in the art, and they are to be included inthe spirit of the present invention.

The various electrode combinations discussed above in relation to thefigures in description of the bipolar mode can also be used, inmonopolar mode simply by connecting both electrode's proximalconnectors, such as 667 and 669 in FIG. 60, to the same side (activeside) of the RF supply, or by connecting the conductor branches leadingto the tips together, as in FIG. 52, and connecting the resultant singleconductor to the RF supply. As described above, in monopolar mode, thereturn path (return electrode) is through a conductive surfaceadjacent/attached to the patient's exterior body surface with aconductor leading from there to the RF supply. All of these combinationsare included in the present invention.

Although the present invention has been described above in terms of aspecific embodiment, it is anticipated that alterations andmodifications thereof will no doubt become apparent to those skilled inthe art. It is therefore intended that the following claims beinterpreted as covering all such alterations and modifications as fallwithin the true spirit and scope of the invention.

What is claimed is:
 1. An RF electrode device comprising: (a) electrodetip module means including first tip means for conducting RF energy tobody tissue; (b) electrode stem means including i) first conductor meansfor electrically connecting said first tip means at a distal end of saidfirst conductor means to a first connective means at a proximal end ofsaid first conductor means for connection to a first side of a source ofRF energy; ii) insulative means for electrically insulating a portion ofsaid first conductor means; iii) telescope guide means for guiding anendoscopic telescope, said guide means constructed of electricallyinsulative material.
 2. An RF electrode device as recited in claim 1wherein said telescope guide means has a saddle shape.
 3. An RFelectrode device as recited in claim 1 wherein said first tip means is awire loop.
 4. An RF electrode device as recited in claim 1 wherein (a)said electrode tip module means includes a second tip means forreceiving energy from said body tissue; and (b) said electrode stemmeans further includes (i) second conductor means for electricallyconnecting said second tip means at a distal end of said secondconductor to a second conductive means at a proximal end of said firstconductor means for connecting to a second side of said source of RFenergy; and (ii) insulative means for electrically insulating a portionof said second conductor means.
 5. An RF electrode device as recited inclaim 4 wherein said electrode stem means further includes (i) secondconductor means for electrically connecting said second tip means at adistal end of said second conductor means to a second connective meansat said proximal end of said second conductor means for connection to asecond side at a source of RF energy; and (ii) wherein said insulativemeans further insulates a portion of said second conductor means.
 6. AnRF electrode device as recited in claim 1 wherein said first tip meansis a needle.
 7. An RF electrode device as recited in claim 1 whereinsaid first tip means is a roller.
 8. An RF electrode device as recitedin claim 7 wherein said roller has extremities of smaller area providingRF field enhancement.
 9. An RF electrode device as recited in claim 7further comprising connecting means for removably connecting saidelectrode tip module means from said electrode stem means.
 10. A methodof operating an endoscopic surgical instrument for tissue treatment byapplication of RF energy comprising: (a) depositing an electricallyconductive fluid on a body tissue; (b) applying an active side of an RFenergy source to an electrode tip for contact with said tissue and saidfluid at a first position; and (c) receiving RF energy passed throughsaid tissue and said fluid to a second position for return to a passiveside of said RF energy source.
 11. A method as recited in claim 10wherein said conductive fluid is a saline solution.
 12. A method asrecited in claim 10 wherein said receiving includes conduction of saidRF energy through a portion of a housing of said endoscopic surgicalinstrument.
 13. A method as recited in claim 10 wherein said applying isperformed by conduction of said RF energy to said tissue and fluidthrough a first RF electrode tip, and said receiving includes conductionof said RF energy through a second RF electrode tip.
 14. A method asrecited in claim 10 wherein said receiving includes conduction of saidRF energy through a conductive pad on an exterior portion of a patient'sbody.
 15. An endoscopic surgical instrument comprising: (a) an endoscopehousing having an elongated housing means for insertion into a bodycavity, said housing means having a conduit formed therethrough; (b) anRF electrode device for installation through said conduit including (i)electrode tip module means including first tip means for conducting RFenergy to body tissue; (ii) electrode stem means including a) firstconductor means for electrically connecting said first tip means at adistal end of said first conductor means to a first connective means ata proximal end of said first conductor means for connection to a firstside of a source of RF energy; and b) insulative means for electricallyinsulating a portion of said first conductor means.
 16. An endoscopicsurgical instrument as recited in claim 15 further comprising: (a)conductive element means having second connection means for electricallyconnecting said conductive element means to a second side of said sourceof RF energy; whereby said endoscopic surgical instrument is operableupon connection to said RF energy source to cause RF energy to passbetween said first tip means and said conductive element means.
 17. Anendoscope surgical instrument as recited in claim 16 wherein saidconductive element is a conductive pad means for attachment to anexterior body portion of a patient to be treated; whereby saidendoscopic surgical instrument is operable in a monopolar mode whereinRF energy from said RF energy source can pass between said tip means andsaid conductive pad means.
 18. An endoscopic surgical instrument asrecited in claim 17 further comprising fluid supply means for directinga fluid through said conduit and out said distal end of said conduit.19. An endoscopic surgical instrument as recited in claim 18 whereinsaid fluid is non-isotonic.
 20. An endoscopic surgical instrument asrecited in claim 18 wherein said fluid is isotonic for enhancingelectrical current between said first tip means and said conductiveelement.
 21. An endoscopic surgical instrument as recited in claim 16wherein said conductive element is a conductive means included as partof said elongated housing means; whereby said endoscopic surgicalinstrument is operable upon connection to said RF energy source to causeRF energy to pass between said first tip means and said conductive meansand thereby operate in a bipolar mode.
 22. An endoscopic surgicalinstrument as recited in claim 21 further comprising fluid supply meansfor directing a fluid through said conduit and out said distal end ofsaid conduit.
 23. An endoscopic surgical instrument as recited in claim22 wherein said fluid is non-isotonic.
 24. An endoscopic surgicalinstrument as recited in claim 22 wherein said fluid is isotonic forenhancing electrical current between said first tip means and saidconductive element.
 25. An endoscopic surgical instrument as recited inclaim 16 wherein said conductive element is a second tip means forextension from a distal end of said conduit; whereby said endoscopicsurgical instrument is operable upon connection to said RF energy sourceto cause RF to pass between said first tip means to said second tipmeans and thereby operate in a bipolar mode to treat a localized are oftissue.
 26. An endoscopic instrument as recited in claim 25 furthercomprising fluid supply means for directing a fluid through said conduitand out said distal end of said conduit.
 27. An endoscopic instrument asrecited in claim 26 wherein said fluid is non-isotonic.
 28. Anendoscopic instrument as recited in claim 26 wherein said fluid isisotonic for enhancing electrical current between said first tip meansand said second tip means.